[CT Birds] subject- species declines

COMINS, Patrick PCOMINS at audubon.org
Tue Mar 20 07:36:47 EDT 2007


A great tool for exploring bird population changes over time is the Breeding Bird Survey Results and Analysis page: 
http://www.mbr-pwrc.usgs.gov/bbs/ 

Simply click on the first "trend estimates" link, which leads you here: 
http://www.mbr-pwrc.usgs.gov/bbs/specl05.html 

Choose the species in question and you get a whole list of areas that you can see the trends for, along with the disclaimers as to how statistically significant the numbers are for each species (the lower the p value, the better the chances that the trend is real, generally P<0.05 is considered a good trend).  Keep in mind that even a small declining trend of say 2% annually can result in big changes over the long-term.  Wood Thrush is a good example of this:

http://www.mbr-pwrc.usgs.gov/cgi-bin/plotpgm0.pl?/sula/jrs/bbs05/htmind/07550.con 
The points are a little scattered, but a -1.4% annual decline has meant that on average there are about half as many reports per route as were reported in the late '60's.  

For Blue-winged Warbler at -3.4% (and a more accurate p value), the declines have really added up: 
http://www.mbr-pwrc.usgs.gov/cgi-bin/plotpgm0.pl?/sula/jrs/bbs05/htmind/06410.con 

They also have trend maps, that can be easier to navigate: 
http://www.mbr-pwrc.usgs.gov/bbs/htm03/trend2003_v2.html 

 

Joe Zeranski and I have also provided an analysis of the Summer Bird Count data focusing on species for which long-term trends are becoming apparent in the last few years SBC issues of the CT Warbler , and data from both of these counts were used to do the trend analysis for last year's State of the Birds report.

Patrick Comins, Meriden 




-----Original Message----- 
From: ctbirds-bounces at lists.ctbirding.org 
[mailto:ctbirds-bounces at lists.ctbirding.org]On Behalf Of Carrier 
Graphics 
Sent: Sunday, March 18, 2007 1:07 PM 
To: ctbirds at lists.ctbirding.org 
Subject: [CT Birds] subject- species declines 


From: Paul Carrier: 

I have received so many responses on the comment of abundance of birds seen "back when", here in 
CT -  thank you all. 
 I just hope this might enlighten all of us on just what might be the "Big Picture" as to why we 
are seeing such a decline of birds in so many short years. This is not all caused by natural 
change, it is in fact, - US -  who are accelerating this decline. We need to see this, and when we 
do, honestly take the blame for it.................... We can't have it both ways - Human 
proliferation while enjoying a natural abundance of wildlife. Its that simple. 

On the brighter side: Another "Back When".  

On May 19th, 1973 -  Seen in one lone large Oak tree adjacent to the woods on the lawn of the CT 
General grounds in Bloomfield,CT, myself and two other birdwatchers from Hartford Audubon Society 
counted, in less then 5 mins :- 3 Parulas, 2 Chestnut -sided, 1 Blue-winged, 8 BT Greens, 2 Pine, 
5 Yellow-rumped (should still be "Myrtle"), 1 Magnolia, 1 Prairie, 1 Wilson's, 2 Nashville, 3 
Bay-breasted, 1 Blk & White, 2 Blk Poll, 2 Blackburnian, 1 BT Blue, 2 Tennessee, and 3 Redstarts = 
17 Warbler species in one tree! And that was just the Warblers! 
  Their were also many, many more numbers and species all around this tree as well. I noted it as 
"a very big wave of birds" 
Sadly: This tree and the adjacent woods surrounding it have since been cut down. 
  

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	-----Original Message----- 
	From: ctbirds-bounces at lists.ctbirding.org on behalf of DBOBOLINK at aol.com 
	Sent: Tue 3/20/2007 6:19 AM 
	To: ctbirds at lists.ctbirding.org 
	Cc: 
	Subject: [CT Birds] Pawcatuck Birds
	
	

	3/19 - Pawcatuck, River Rd. Shoreline Access Area - BROWN THRASHER, WILSON'S
	SNIPE, AMERICAN WOODCOCK. Also on River Rd., EASTERN PHOEBE.
	Sterling, Backyard Feeders - FOX SPARROW (10).
	
	Robert Dixon
	Sterling, Ct.
	
	
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